No, this is just a really massive external hard drive with a RAID0 (no redundancy) or RAID1 setup (mirroring of data), which means you have 8TB of data storage left over. This disc is not a NAS.

This would be a NAS that would also be expandable, Synology DS418 with 4 x 2TB hard drives:

Synology DS418 (4 x 2TB, WD Red Plus)